Sql updating multiple tables simultaneously updating web content
While this is certainly something to watch out for, more commonly we might just want to join in a table to decide which rows we want to update.Suppose we only want to update rows in queries involving multiple tables can be quite difficult to write correctly.SELECT * FROM table_1 CROSS JOIN table_2;-- id | value1 | id | value2-- ---- -------- ---- ---------- 1 | a | 1 | W-- 1 | a | 1 | X-- 1 | a | 3 | Y-- 1 | a | 5 | Z-- 2 | b | 1 | W-- 2 | b | 1 | X-- 2 | b | 3 | Y-- 2 | b | 5 | Z-- 3 | c | 1 | W-- 3 | c | 1 | X-- 3 | c | 3 | Y-- 3 | c | 5 | ZSELECT * FROM table_1, table_2;-- id | value1 | id | value2-- ---- -------- ---- ---------- 1 | a | 1 | W-- 1 | a | 1 | X-- 1 | a | 3 | Y-- 1 | a | 5 | Z-- 2 | b | 1 | W-- 2 | b | 1 | X-- 2 | b | 3 | Y-- 2 | b | 5 | Z-- 3 | c | 1 | W-- 3 | c | 1 | X-- 3 | c | 3 | Y-- 3 | c | 5 | Z are equivalent.
Tr_Num SET = 1 where case when rest.class ='AC I' then res.book=1 when rest.class ='AC II' then res.book=1 when rest.class ='AC III' then res.book=1 end UPDATE res INNER JOIN rest ON = rest. PNR = 5; However, and maybe I misunderstand, but I suspect what you really want to do is actually an INSERT an UPDATE in a single transaction. Other DB sessions looking at the tables will always see the results of either none or all of the updates in the transaction (assuming you're not using the non-default transaction isolation level).
Tr_Num SET = 1, = 21 WHERE (rest.class ='AC I' OR rest.class ='AC II' OR rest.class ='AC III') AND rest.
column PNR =Primary Key This table takes input from users. Refer to the documentation for the CREATE PROCEDURE syntax for details and/or see e.g. Note that it's still a good idea to wrap the two statements in a transaction inside the stored procedure.
You want to INSERT a new row into 'rest', and then update the relevant numbers in 'res'. There is not really a good way to do an INSERT and an UPDATE in a single query, except you could wrap the two statements in a stored procedure, and then call that stored procedure to execute both statements in one go.
Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. of tickets at the begging, book= tickets booked and bal=balance of tickets from the total tickets) which describe against which Train how many tickets are available, how many were booked and what's the current balance when the user is logged in to book their tickets. My question is how to update table res and update columns which is created to store the tickets booked for each class and for a particular train name or train number.
Visit Stack Exchange Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. Sign up to join this community Primary Key This table holds all the information related to Train Journey. For example: IF customer books a seat in TRAIN NAME ='A', CLASS='AB' then my other table with the same row having a column "BOOK" will auto-increment.
In this tip we will walk through how to use the MERGE statement and do this in one pass.
Beginning with SQL Server 2008, you can use MERGE command to perform these operations in a single statement.
The new MERGE command looks like as below: The MERGE statement basically works as separate INSERT, UPDATE, and DELETE statements all within the same statement.
You specify a "Source" record set and a "Target" table and the join between the two.
You then specify the type of data modification that is to occur when the records between the two data are matched or are not matched.Tags: Adult Dating, affair dating, sex dating